(a) Field of the Invention
This invention relates to side guards or rails for beds. More particularly, it relates to such side guards or rails which are movable between two differently-oriented, positively-stopped and locked positions, and to mechanisms to enable the moving of the rails between such positions. One particularly useful such rail is for hospital beds. However, the assist and guard rail is useful for all beds having a side rail framework.
(b) Description of the Prior Art
As noted above, one particular use for such rail is for hospital beds. Hospital beds had rails along the sides thereof for two purposes. One purpose of such bed rail structure along the edges of the bed was to prevent the patient from falling out of bed. The early prior art devices that were employed for this purpose used rigid frame members that were clamped, when in use, to the side of the bed. While these devices seemed to serve the purpose for which they were intended, they brought about the disadvantage that they made it difficult to treat the patient and also caused considerable difficulty during the changing of the sheets or blankets on the bed.
To provide an alleged improvement over such primitive devices, standard hospital-type beds generally now include side rails which may be of two types. One type comprised a single-piece tubular side rail structure which extended substantially the length of the bed and which must be lifted off to allow the patient to be moved, or, if the patient was movable, to allow the patient to exit or to enter the bed. The other typical type comprised a similar side rail structure which had a complicated and expensive hinged mechanism to allow the side rail to be lowered to the floor. This was thought to be more convenient for the aide, but it was impossible for the patient to manoeuvre if the patient was in the bed.
Accordingly, the art next developed bed rail devices that were, in a sense, retractable so that the rail devices could either be placed in an "up" position or could be moved to a "down" position, in order to render the top surface of the bed easily accessible. Safety bed rails and side guards which were especially adapted to prevent persons from falling out of bed are thus How well known. Various constructions of such bed guards provided such bed guards which were movable between a raised position, in which the bed guard was supported at a level above the surface of the bed mattress and a retracted or lowered position in which the bed guard was either moved out of the way toward one end of the bed, or was lowered to a position below the mattress.
Several other types and forms of retractable devices have also been provided, but they have been found to have one or more of the following disadvantages. First, in several types of such devices of the prior art, the bed rail mechanism was not movable through a vertical plane that was parallel to the edge of the bed. In such cases, it was necessary that the bed be moved from its position against the wall in order to effectuate retraction of the guard rail.
Secondly, most of the known prior art devices are not equipped to withstand force applied horizontally thereof. More specifically, it has been found that most prior art devices having retractable features provided adequate support against accidental pivoting through the intended plane of movement, there had, in the past, been no adequate provision for withstanding force applied normal to the direction of the intended movement.
While many types of operating mechanisms have been previously devised for movable bed guards, such prior bed guards have been susceptible to pinching or otherwise injuring the extremity of the attending person who operates the lowering or retracting mechanism. Thus, it was necessary to operate such devices carefully to prevent injury.
Parallel links or arms constitute one arrangement for supporting a side guard so that it will move easily between the two positions. In this arrangement, two parallel arms extended between the side guard and the movable back section on which the head end of the mattress rested, those links being of equal length and rotatably connected both to the side guard and the back section. Thus, the side guard moved upwardly or downwardly when the links rotated, yet remained at the same angle with respect to the back section. In order to enable the side guard to rise high enough to be effective in its purpose, and still to drop low enough so as not to interfere with the changing of sheets or the replacement of a mattress, the two parallel arms must be quite long. This, however, detracted from the stability of the side guard, making it somewhat wobbly in its upper position. It further caused the side guard to undergo a lengthy translational movement when passing between the two positions, and this requires considerable clearance at the end of the side guard.
In parallelogram linkages of guard rail structures of the prior art, the upright and horizontal members have been subject to a scissors action, particularly during collapsing movement of the rail structure but also to some extent in raising movement thereof. This required great care on the part of the nurse or other operator of the structure to avoid pinching the fingers or other members of either the operator or the patient. Garments and bedclothes were also apt to be pinched in prior art collapsible side rail structures.
Another typical bed rail mechanism used vertical support members which were slidably attached to the bed frame such that the bed rail can be raised and lowered vertically. These sliding-type mechanisms typically locked the bed rail in the raised position by use of a pin engaging a hole in the vertical support member or by a clamping means. That mechanism had been subject to the loss of component parts. Further, such bed rails can be relatively heavy and awkward for a given operator to raise and lower. If such bed rails were not lowered evenly, they tended to bind, become difficult to move and can jam in an undesired position.
Another purpose of side rails was to assist persons getting into or out of the bed. Many persons, especially as they became older or became infirm, had difficulties in moving from the siting to the standing position and vice versa. Devices have been previously proposed for attachment to a bed to provide a rail which was adjacent to the side of the bed to assist the person. However, the previous designs were generally unsatisfactory for attachment to bed frame arrangements of the type readily available in U.S.A. and Canada and were generally unsatisfactory for providing a stable and readily adjustable support for the person.
The patent literature has provided alleged improvements to the above-described rail systems of hospital beds.
U.S. Pat. No. 2,817,855, patented by Pratt, disclosed a guard frame which was pivotally mounted upon a frame member of a bed and was movable from an upper guarding position to a lower unguarding position by rotating its supporting members around the pivotal mountings.
U.S. Pat. No. 3,021,534, patented Feb. 20, 1962, by Ray K. Hausted, provided an adjustable bed rail assembly which included first and second adaptor brackets which were secured to the side rails. A pair of link arms was pivoted to the brackets and was swingable through a vertical plane. A rigid frame of generally quadrilateral configuration was provided, the frame having adjacent corner portions that were pivoted to the free ends of the link arms, so that the opposed sides of the frame may be moved into and out of position in alignment with the link members upon relative pivotal movement there between. At least one bracket was provided which had a U-shaped pocket within which the link arm which was pivoted thereto may be received, with the link arm being in alignment with an opposed side of the frame.
U.S. Pat. No. 3,055,020, patented Sep. 25, 1962, by Stuart Nelson Mann, provided a restraining structure for beds, which comprised a parallelogram linkage. It included a pair of spaced upright channel members which were disposed with their open side facing with other and which were adapted to be pivoted at their lower ends to the side portion of the framework of a bed. Flanged portions of the channel members had portions projecting therefrom toward the other channel member to form pairs of spaced bearing portions which were offset substantially from the channel members proper. A plurality of vertically-spaced, horizontally-extending tubular members had their ends pivoted between pairs of the bearing portions to form a parallelogram linkage. Stop means were provided for limiting downward pivotal movement of the upright members to a predetermined oblique position. The pivot axes of the bars were offset from the channel members proper by a sufficient distance so that, during collapsing movement of the parallelogram linkage, the approaching sides of the channel members and the tubular members maintained substantial spacing to avoid pinching.
U.S. Pat. No. 3,585,659, patented Jun. 22, 1971, by Francis J. Burst et al, provided a safety side guard for hospital beds. The guard was mounted upon the mattress supporting frame of the bed by mounting means that included trunnions which were journalled in a mounting bracket that was fixed upon the frame. The guard was movable from an elevated guarding position to a lowered inoperative position, causing rotation of the trunnions in their journals. A spring pressed latch which was mounted in the bracket secured the guard in elevated position, and top means limited movement of the guard both up and down. The mounting bracket was mounted on the frame and was disposed well below the patient in the bed, and hence, was not readily accessible to the patient, although it was readily accessible to a nurse when it was desired to lower the guard.
U.S. Pat. No. 3,971,083, patented Jul. 27, 1976, by Warren J. Peterson, provided a side guard for beds which was movable between raised and lowered positions and which included a latch apparatus which could be released with the knee of an attending person in such a manner as to prevent injury of that person's knee during such movement. The safety bed rail assembly included a pivot assembly which was adapted to allow movement between the raised and the lower position without injury to the operator. In its raised position, the safety rail prevented persons in bed from falling out of bed and provided useful assistance in moving into and out of bed. In the lowered position, the guard was positioned below the mattress level to allow a nurse or other bed attendant to tuck bed clothes under the mattress without the rail obstructing the operation and to move easily around the bed and patient to administer injections or other treatments. When so lowered, the rail was spaced sufficiently above the floor to provide clearance for cleaning and movement of stands and the like thereunder.
U.S. Pat. No. 4,612,679, patented Sep. 23, 1986, by Larry D. Mitchell, provided a bed side guard assembly, which was movable between elevated and depressed positions on parallel swing arms that were quite short and extended from a base which was mounted on the back section of the bed. It had an upper section which pivoted outwardly and downwardly to a retracted position substantially to reduce the height of the side guard. When the side guard was in its depressed position with its upper section folded to the retracted position, the side guard lay entirely below the mattress supporting surface of the bed back section and therefore did not interfere with bed making. The parallel swing arms had spindles which projected into the base, where they rotated as the side guard moved between its elevated and depressed positions, and those spindles carried crank arms that were connected by a tie bar. A latch bolt lay in the path of the tie bar to hold the side guard in its elevated position. The tie bar, by coming against one or other of the spindles, prevented the side guard from going past its elevated or depressed positions.
U.S. Pat. No. 4,993,089, patented Feb. 19, 1991, by Robert A. Solomon, et al, provided a bed rail mechanism, wherein a multi-link mechanism was used to attach a bed rail to a bed frame so that the rail could be easily raised to its elevated position and locked in place. Alternatively, the rail could be easily released and placed in the lowered position. The mechanism used a movable framework to guide the bed rail in an arcuate path between its elevated and lower positions. A diagonal linkage was provided to lock the mechanism and bed rail in the elevated position. A counterbalance mechanism was also provided so the operator need not struggle with the weight of the rail.
U.S. Pat. No. 5,216,768, patented Jun. 8, 1993, by Oliver H. Bodine, et al, provided a bed system, which included a patient-operable side rail to be attached to one side of the bed and which was rotatable in a plane which was parallel to the plane of the bed, on the side to which it was attached. The side rail was rotatable so as to serve as a barrier. Rotation of the side rail only 90.degree. was permitted to set the rail into its open stopped position. Optional engagable locking means were manually, but not automatically, operable to lock the rail in the closed position or in the open position.
U.S. Pat. No. 5,381,571, patented Jan. 17, 1995, by Thomas S. Gabbart, provided a pivotal and lockable hospital bed guard, as a closure mounted on a bed rail at a gap. The bed guard was movable between a first position maintaining the gap and a second position closing the gap to prevent patient movement through such gap. The closure had a first end, which included a rotation means, the rotation means being carried by the guard rail. A first lock was provided for securing the closure in a first locking position with the closure means being adapted to be positioned adjacent to, generally parallel to, and coextensive with, the guard rail, thereby maintaining the gap. A second lock was provided for securing the closure in a second locking position closing the gap. The first and the second locks were operated by a single handle. Means were provided for engaging the first and the second locking means.
U.S. Pat. No. 5,384,927, patented Jan. 31, 1995, by Steve Mardero et al., provided a security rail attachment for a bed, which included a post with an adjustable foot at the lower end. A rail portion was mounted within the post and was rotatable about the vertical axis of the post. An attachment rail extended across the end of the bed and included clamping elements for clamping to angle irons along the sides of the bed. The rotatable rail portion could be latched at four 90.degree. spaced-apart positions by notches in the base of a vertical post of the rail portion which cooperated with a transverse pin in the post. The rail portion could therefore project outwardly from the bed at right angles thereto for assisting the occupant in standing, or could lie along the side of the bed to assist the occupant to prevent the occupant from falling from that side of the bed.